The weather is being watched closely by Hettinger as well as Air Boss Mike Riordan.

Production tents can't be set up, and planes in the air show are racing in.

"They're either all rushing in today and getting in before bad weather hits or they won't come in until late Friday or Saturday morning," said Riordan.

But air show practice may not happen. That would've been a problem with military planes, but they won't be here. It's not as much of a problem for civilian planes.

"Civilian aircraft do not since it's what they do for a living. They are aircraft pilots, they are not required to practice," said Riordan.

Security for the show has already begun with Louisville Metro Police scanning under the bridges, the Belle of Louisville and Spirit of Jefferson, and on the grounds, a security plan they've had since 9/11 and the weather isn't affecting that.

"My entire family is coming. I've got grandkids coming. I don't have a worry in the world," said Hettinger.

No matter what the weather, security and the fireworks are set for Thunder Over Louisville this weekend. The forecast looks cool but dry on Saturday.